I have an 82 with a 350, cross fire fuel injection system.
Recently it bogs down on me intermitently especially when I accelerate...
I has died a couple of times, I can wait a minute and it will fire back up.
The check engine light came on but I think that may be due to electrical problems, (the brake light stay on, and the cooling system temp gauge stays pegged on hot. I just purchased the car and it is my first Vette so any help would be greatly appreciated...
hOOtERii

 

Does the cooling system temp gauge return to cold after the engine is turned off for a while.
If not the gauge is shot or the temp sending unit is faulty


If the gauge retuns to cold then your fan maybe on the blink
Maybe your fan belt is slipping.
Also check your fluid level in the radiator

Brake light staying on could be a few different things
Make sure your emergency brake is in the off position.
You could be low on brake fluid
Could be a bad brake switch under you gas pedal

As for the car not runing good it could be a lot of things.
plugs
fuel pump
electrical
Spark plugs
Injection system
Maybe just dirt in the injectors

Good luck,

Schoon

 

have you pulled the codes yet. that would be a good starting point. pull them and post back and we'll see what we can help with. cheers

 

Welcome to the forum.

Might also check the fuel pressure.

 

I don't know much about the injected models. My '81 is the last of the carb models and I dumped the smog pump and quadrajet awhile back. The usual suspects come to mind when you say starving f/ fuel; pump/system pressure at the carb, clogged vent or fuel line, dry-rotted rubber line. It's a trial and error thing. From the tubes in the tank to the carb, right on up the line, and over to the canister where the vent runs into ofcourse. Have you read the plugs? That's something I always do first, as they can tell you things about how the engine is running overall w/o using any instruments. Good Luck.

 

Hi,
1. First I would check the engine timing. Believe factory idle is at 500 RPM in Drive, but I use 600 RPM in Park with A/C On since I don't have anyone to step on the brakes.
A. 1st disconnect the single wire connector with the tan w/ blk stripe wire on the driver side of the distributor; it is the EST distributor by-pass to run the distributor at base timing.
B. Set the idle to 600 RPM by adjusting the idle adjustment screw- the rear TBI passenger-side has an adjusting screw.
C. Set the initial timing at 6 degrees advance BTC.
D. Check idle again after re-adjusting timing @600 RPM.
E. Re-connect the by-pass connector after setting initial timing.
2. Adjust TPS (Throttle Position Sensor) on rear TBI with a voltmeter to .525 volts. The TPS setting affects the fuel pulses from the ECM to the dual TBI injectors.
Re-adjust idle again to 600 RPM & re-check TPS voltage.

If engine still runs crappy:
1/ Change the O2 sensor if your Corvette has 60K or more miles. The O2 sensor will lean out/run rich improperly if it is failing & sends erratic voltage signals to the ECM.
2/ Check the Coolant Temperature Sensor (CTS) in the front of the intake manifold & just under the air injection pump. Sometimes the 2 wires are damaged from resting the air injection pump on the engine when changing the water pump and the insulation or wires themselves are damaged. The CTS controls the open/closed loop operation of the ECM & the ECM needs the CTS voltage signal to run properly.
3/ I would check the fuel pressure from the fuel pump, but since this involves setting up an in-line fuel pressure gauge I would just put one in permanently.
Sounds like your fuel pump is failing.
Xtreme-FI, an eBay seller, sells an adjustable 8-40# fuel pressure regulator and a T-connector to hook-up an in-line fuel pressure gauge. Pressure can be adjusted with an Allen wrench from the top of the rear TBI with no hassles. Be sure to get a fuel pressure gauge with liquid inside to stablilze the needle when the engine is running.
Most factory fuel pumps have a hard time maintaining the 12 PSI for the dual TBI's and as engine RPM increases, the TBI's starve out. Recommendation is a steady 14 PSI in all RPM ranges.
I'm planning to purchase an 85-87 Corvette fuel pump and adjust the pressure down to 14 PSI using the Xtreme-FI fuel pressure regulator and getting a fuel pressure gauge since my stock '82 fuel pump leans out the fuel mixture.

Other causes for a rough idle are worn throttle shafts in the TBI's which can be re-bushed (if the throttle shaft wiggles a lot in the TBI base, it's worn), malfunctioning EGR valve (leaking vacuum or stuck open with carbon build-up), broken or damaged intake gasket in the top cover of the crossfire intake, un-balanced dual TBI's.
Crossfire TBI's can be balanced using DIY materials for a water manometer.

Hope this helps.

 

Change the engine thermostat to 195F.
I've run across new thermostats that won't open @195F & went above 220F before opening so had to return & replace with another "new" one.
195F is where the ECM will go into its closed loop programming to run the engine using the engine sensors.

On the side of the passenger side head below the exhaust manifold is the termperature sending unit for the electric radiator fan. Believe when it reads 220F, it kicks the electric fan on. The sensor provides a ground for the fan motor when it connects @220F.
I just grounded the wire to the sensor as I always run my A/C and want the A/C condensor cool to save the A/C compressor from overheating.
There are radiator fan temperature sensors that opens @195F also from Mid-America Corvettes.

Retarded timing can also overheat the engine so check the base timing.

 

A way to check the throttle shafts for wear is to spray some carb cleaner at each opening around the shaft. If you see a change in RPM on a hand-held tach, then they need to be rebushed. Can also use a unlit propane torch.

 

I purchased an OBD1 to USB interface cable to plug the interface cable into the ALDL diagnostic plug behind the console ashtray to connect a WinXP laptop to check if the engine sensors are working within the voltage parameters.
There's some free software online to install on the Win2000, WinXP, Vista operating system.

The stock ECM chip is not programmable since it can be flashed only once & was done at the factory, but it will work fine with the factory cam or with an aftermarket mild performance cam from Lunati or Comp Cams which are designed for OEM computerized fuel management systems.

Another way is to purchased an ALDL code reader which just plugs into the ALDL port behind the console ashtray and with engine off/ignition on, the Check Engine light will pulse out any trouble codes.
The first code to come up is Code 12 - Normal Operation. The Check Engine Light will pulse 1 flash then 2 flashes with a somewhat long interval for the next code if there is any trouble.
Engine codes for the TBI can be found at: http://tvoffer.tripod.com/gmcodes.htm